This is extension for Flycheck. It displays Flycheck error messages in buffer using `popup.el' library. For more information about Flycheck: http://www.flycheck.org/ https://github.com/flycheck/flycheck For more information about this Flycheck extension: https://github.com/flycheck/flycheck-popup-tip ;; Setup Add to your `init.el': (with-eval-after-load 'flycheck '(add-hook 'flycheck-mode-hook 'flycheck-popup-tip-mode))